Hope this is the correct location to ask this question. I have Futaba servos installed in a Funtana 125. The aliron (2), the elevator(2), and rudder(1) servos all require extension cables. I have been told that there is considerable voltage loss through the male/female connectors. Can I eliminate the connectors and solder the extension to the servo leads? Is there a special solder that should be used? Should the solder connections be off set?

Solder all you like. Offset not needed if shrink tube used, but it's OK for insurance. Solder for electronics rosin core.

Or just use 6.6v life packs.<br type="_moz" />

Thanks. I understand about the soldering and will give it a go. However, these are Futaba 3305 servos that call for NiCAD batteries only. Either 4.8 or 6.0 volts. Have been told that using the life pack will harm the servos. Your thoughts on this issue?

Imake my extensions now a dayswith the replacement and crimpers, more cost effective and it is a cleaner install when made to length. But it really does not make any difference whether soldered or stock. As for volts, follow the mfg's specs always.

Soldering is fine for servo extensions. If the extension is too long, the server will not center properly, regardless of how the extension is done. This depends on the type of the servo and the length of the extension. Suggest to test it first via the connector extension before cut the wire.

If you do need an extra connector (wing removal)I recommend the deans micro. They are far better than the standard servo connectors and will give you minimal voltage drop.

While what you're doing won't hurt anything (unless you botch the soldering job ) it's not needed.

Most of us run long extensions in GS planes and there's really no problem doing so, what you're doing isn't that big in the grand scheme. My Funtana had the recommeded extensions and flew fine for years.

I have used a LIFE battery pack with several Futaba servos, but not the 3305. There are some NiMH batteries, though being high capacity packs, that don't supply the amperage a high torque servo will need. Most servos rated for 6V packs do fine with a LIFE. You may want to look at the switches you use, some that are fine for standard servos may be a bottle neck for a higher amperage set up.

I'm not recommending going against what's recommended but I will say.........

A 6 volt nimh or nicd fully charged is 1.45x5=7.25 volts. A life pack fully charged is maybe 7.4 volts for a few moments and settles into 6.8-6.9 fully charged, so I don't see the problem.

Has not been a problem on Hitec standard servos but can't speak to Futaba.

You might lose point/something... in volts by adding the extensions.



From Towers site

"This is the Futaba S3305 High Torque, Metal Gear Servo. per Futaba this servo is approved for use with NiCd batteries ONLY!
This servo can produce high-current draw from your batteries. If using NiMH or LiPo batteries, make sure they are capable of delivering sufficient amps. "
<pre>


SO the point is to use batteries that can provide the current draw and LIFE certainly can.

They are warning against hi capacity nimh with high internal resistance that can't provide the amps draw!!</p></pre>

FWIW, I agree completely. 40% gas 3D or 1/5.8 A10 with 48" leads X 2. Never a funtcional problem. I thought about soldering earlier with the A10 but with the concern of any heat that could melt insulation and cause contact across the wires, I decided not to go that way. You can also crimp very reliably if you try a few to get warmed up on and make your own. I cant remember rigth now where I got mine but if you are interested I can post a good source for crimping pliers.


Good luck
Dave

Thanks Everyone: I think it was age getting to the elevator and rudder servos. I removed the 2 elevator servos and the 1 rudder servo. Unplugged from the receiver and removed the servos and cables. At the coupling for the extensions, I had to remove the heat shrink that I had installed to keep them together, then unplugged the connections and cleaned them. Put them back together and used connector clips, reinstalled all the servos and everything works great. All-in-all, I think the connections were just dirty or maybe a little corroded.

Were youconnecting/disconnectingthe connector frequently?

No: this connector is half way back in the fuselage. Been there for about 3 years.

As Post #10 above shows, it is not good practice to have any connector buried where it is never or seldom exercised. Even the gold plated one can increase in impedance and cause servo jitters or malfunction if never excercised. If you do not occasionally unplug/plug the connections, you are safer with a soldered in extension.

Very often, servos in wings need extensions in order to reach the hole in the center of the wing. I generally Shrink Wrap those connections and leave them that way for years without issue.

What is the definition of "Considerable".. yes there is a voltage drop due to the resistance of the connector, but not that significant...There is also a resistance created with a soldered connection. I just don't think it is worth worrying about... I use long extensions appropriate for the needed length and plug my servos... I used to make up "perfect" extensions, but the time was more than it was worth doing.

If you buy good quality extensions with Gold Plated pins and 20ga wire, you should not have a need to solder the extensions to the servo wires. I prefer to minimize the number of connectors between the servo and the Rx, but you can usually buy extensions that are long enough to require just one extension. If not, use a second one. It is not a big deal.

You could also use heavy duty extensions for better current flow for the bennafit of the doubt.

I fly turbines all day long with A123 Batteries @ 6.6 volts. No Problem. Even on long runs you will burn up the servo before you burn up the wire.

If you are looking for good extensions and connectors, I recommend www.taildraggerrc.com/servo-extensions-servo-arms-and-servo-accesories.htmlHis 20AWG extensions and MPX connectors are the best I have found (and a good price) .

Harry<br type="_moz" />